한 015B

015B (공일오비) is a South Korean Boy Group that debuted in 1990. They consist of 2 members: Jang Hoil and Jeong Seokwon.

015B was formed in 1990 by brothers Jeong Seokwon and Jang Hoil following the disbandment of their previous band, Infinite Track, which had won the 1988 MBC Campus Music Festival. The group made history in the Korean music scene by becoming the first to adopt a "guest vocalist" system, where the core members produced the music and recruited different singers for each track instead of having a fixed lead vocalist. This innovative approach allowed them to explore a vast range of genres, from synth-pop and soft rock to electronica and jazz, making them one of the most influential acts of the 1990s.

Their early years were marked by a commitment to high-quality studio production and sophisticated lyrical themes that resonated with the urban youth of the era. After a long hiatus that began in 1996, the group made a successful return in 2006 and has since continued their guest vocalist legacy through the "New Edition" and "The Year" series, collaborating with both legendary veterans and emerging indie artists.

Their history is defined by their transition from a chart-topping mainstream powerhouse to a respected production-centered duo that continues to shape the experimental landscape of Korean pop music.